That depends on the mountains. If you're happy with 0.5km-1km accuracy, you're probably good to go.
Sorry, but I think you are deliberately minimizing my point and I'm not sure why? GPS is approved as primary source of air navingation (I can provide links to legal texts if you like) Four billion air passengers are happy with this. 4,000,000,000 passengers with
zero deaths in commercial passenger jets last year. Would you agree with me that GPS works well in Aviation?
You should remember that, for obvious reasons, GPS precision will drop dramatically as you approach the mountain.
This is actually untrue and contrary to Flat Earth Empirical Evidence guidelines. The alternative means of navigation are: Non-Directional Beacons (NDB), or VOR's. They are proven to drop dramatically in precision as you approach the mountain, where as GPS maintains it accuracy as proven in aviation.
"Extremely precise" is an overstatement, and your figures appear to have been sourced from the Moon, but yes, synchronising your receiver's clock with the GPS is generally a pre-requisite for GPS working at all. If I were you, I'd propose NTP for a much more practical source of time.
Please as fellow Flat Earther I can't believe what you say. You say 10ns is overstated as "Extremely precise", but you advise using NTP with has an accuracy of 1 ms at best??? You seem to be clever in other posts, why this statement?
No, I'm not talking about the Moon, as Flat Earther I don't believe we can get to the moon. I'm talking about a receiver that I have done some work with and empirically determined to work. An current example is this receiver that gives 15 ns accuracy:
http://www.trimble.com/Timing/RES-SMT-360.aspx that you can buy here quite cheap:
https://novotech.com/Products/gps-timing/Trimble/modulesPete, are you aware that GPS is used in various applications to generate an extremely precise time?
Also, I'm interested in what defines a 'well' working navigation system for you?
The contention we're currently discussing has been outlined within the first two posts of the thread.
No, you said the contention was if GPS works well or not. I'll quote:
Allow me to remind everyone that the key contention here is whether GPS works well or not.
So I ask you, what defines a 'well' working navigation system for you? It's obviously a very vague term. In the Middle Ages the way sail ships navigated worked "well", in the sixties navigation by NDB (non-directional radio beacons) worked well, or dead-reckoning. However these days we wouldn't even consider these inaccurate methods if we can avoid it.